The Port of Seattle oversees both an airport (Seattle-Tacoma International, or Sea-Tac) and a seaport. The agency's aviation division sees more than 30 million passengers a year. The seaport division serves more than 20 shipping lines that transport both containerized and bulk cargo. It also handles calls from cruise ships. In addition, the seaport division oversees commercial fishing, marinas, and portside commercial properties. Most of the agency's revenue comes from airport operations. The Port of Seattle is run by a five-member commission elected by King County voters.